Exploring bioimpendance instrumentation for the characterization of open tubular liquid chromatography columns

Open tubular liquid chromatography columns with organic polymer layers can be powerful tools for high sensitivity measurements in e.g. proteomics. However, these narrow columns are challenging to characterize. A two-electrode system, often used for bioimpendance measurements, was used to study poly(styrene-co-divinylbenzene = PS-DVB) polymer layered open tubular (PLOT) liquid chromatography columns with 10 μm inner diameters. The system performed electrical resistance measurements (ERM) for assessing layer thickness and porosity. Layer determination results were comparable (but more precise) to that obtained with scanning electron microscopy (SEM). Porosity examinations with ERM casted doubt on the presence/availability of pores in the layers investigated.